The invention relates to foamed articles including a polyolefinic polymer and maleic anhydride.
Generally, polymer materials can be used to produce a variety of articles including foamed articles. Foamed polymeric materials have a variety of uses. For example, natural rubber latex foamed articles provide soft materials for body contact and the application of cosmetics. Polyvinyl chloride (PVC) plastisol foamed articles can have a soft, durable feel that simulates leather to the touch. Open cell foamed articles based on polyurethanes have been made suitable for many applications, such as cushions for packaging, automotive applications, home bedding, filters (e.g., for air conditioners), applicators (e.g., for shoe polish), or sound attenuating panels (e.g., for rooms or acoustic speakers).
A variety of polyolefinic polymers may generally be used for each application. However, a polymer which may be desirable for one property, such as cost, may provide a lower quality end product, such as a foamed article with significant voiding.
For example ethylene-propylene diene monomer terpolymer (EPDM) is a desirable material, due to its superior temperature resistance, weather resistance, crosslinking, and non-corrosive properties. However, foamed products utilizing significant quantities of ethylene-propylene diene monomer terpolymer can exhibit poor physical characteristics, such as tackiness or incomplete cell formation, rendering them unsuitable for certain applications. Other polymers, such as high vinyl acetate content ethylene-vinyl acetate (EVA) and ethylene-acrylic elastomers, can be unsuitable for use in certain applications. Ethylene-acrylic elastomers, for example, can provide a soft hand and excellent temperature properties, but the polymeric mixture generally exhibits sticking and blocking, and as such can be difficult to process.
Further, during production, significant amounts of polymer material are frequently cut or removed from the end product. This material can be known as reclaim. It can be difficult to incorporate reclaim materials, such as crosslinked reclaim, into foamed products.